If I attack with multiple units that have triggered abilities targeting the same unit with Deflect, do I have to pay the Deflect cost for each trigger?

Ruling: You must pay the Deflect cost separately for each triggered ability that targets the unit with Deflect. However, you are not required to pay for all triggers—you may decline to pay the cost for any triggered ability, and that ability will be removed from the chain without effect.

Sequence:

• When you attack with multiple units that have "When I attack" triggered abilities, each trigger is placed on the chain as a Pending Item.
• As you finalize each trigger, if you choose to target a unit with Deflect, that trigger incurs an additional cost equal to the Deflect value.
• For each trigger, you may choose to pay the Deflect cost (allowing the ability to become a Chain Item) or decline to pay (removing that ability from the chain per Rule 404.2).
• Only the triggers you paid for will resolve.

Nuances:

• Each instance of choosing a unit with Deflect triggers the Deflect cost separately, even if multiple abilities target the same unit.
• Since a unit that is already stunned cannot be stunned again, there is typically no benefit to paying for multiple stun triggers targeting the same unit.